With the continuing trend toward compact electronic apparatus, there is an ever-increasing demand for miniaturized interconnection systems between the electronic components of the apparatus. An example is in computer apparatus wherein there is a constant demand to reduce the thickness or height parameters of the electronic components. With the components mounted on a printed circuit board, the thickness or height parameters relate to the distance above the board in which desired interconnections are made and which constantly are being miniaturized.
One approach to such miniaturization is to eliminate bulky electrical connector housings and, instead, to use relatively thin connectors or connector blocks for locating and/or terminating tail portions of terminals relative to circuit traces on the printed circuit board. The tails may be soldered to circuit traces on the board or in the holes, and a complementary connector assembly may be mounted directly to the connector block or interconnected thereto by terminal pins extending through the holes in the printed circuit board from the opposite side of the board.
Problems continue to be encountered in handling such connector assemblies for mounting to a mounting surface of an electrical apparatus, such as positioning the connector assembly on the printed circuit board. As is known, a solder reflow process often is used to secure electrical connectors to printed circuit boards. It has become expedient to use a vacuum-suction nozzle for handling the electrical connector to position the connector on the circuit board prior to the solder reflow process. Specifically, an electrical connector is secured by a vacuum-suction nozzle, and the electrical connector is manipulated in position and brought to a selected position on the printed circuit board by the vacuum-suction nozzle. The connector then is released by the nozzle by stopping application of negative pressure thereto. Gas then is released inside the soldering reflow vessel, or infrared rays are radiated therein until the solder applied to selected conductors on the printed circuit board has been melted, thereby soldering the selected conductors to solder tails of the electrical connector.
Such a system involving the use of a vacuum-suction nozzle is quite effective if the electrical connector has a smooth or flat top surface for securement by the vacuum-suction nozzle, as described above. However, connector assemblies often have top surfaces taken up substantially by closely spaced open ends of terminal-receiving passages through the connector housing and, therefore, there is no smooth surface for direct engagement by the vacuum-suction nozzle. An example of such a connector assembly is where open-ended or through passages are formed in the housing with terminal receptacles top-loaded into the passages. During mating, terminal pins of a complementary electrical connector extend through the printed circuit board and into the bottom of the passages containing the terminal receptacles. With such connector assemblies, there is no smooth surface for engagement by the vacuum-suction nozzle.
Consequently, it has been proposed to employ a separate cover which presents a smooth top surface for engagement by the vacuum-suction nozzle, the cover being releasably interengaged with the terminals of the connector assembly. After the connector assembly is brought to a selected position on the printed circuit board by the vacuum-suction nozzle, and after the solder reflow process, the separate cover is removed and the connector assembly is left interconnected to the printed circuit board by the soldering of the terminal tails to the selected circuit traces on the printed circuit board.
The present invention is directed to an improved system of the character described, by employing a simple adhesive-backed film adhered to the top surface of a connector assembly covering the top ends of the terminal-receiving passages therein, and presenting a smooth surface for engagement by a vacuum-suction nozzle.